The present invention relates to a chewable or disintegrative tablet prepared by forming a tablet having a friability of less than about 2% from a mixture comprising a pharmaceutically active ingredient, an excipient in the form of a hydrate, and a water-swellable excipient, and then applying sufficient energy to the tablet for a sufficient time to decrease the hardness of the tablet by at least about 20%.
Pharmaceuticals intended for oral administration are typically provided in solid form as tablets, capsules, pills, lozenges, or granules. Tablets are swallowed whole, chewed in the mouth, or dissolved in the oral cavity. Chewable or disintegrative tablets are often employed in the administration of pharmaceuticals where it is impractical to provide a tablet for swallowing whole, for instance with pediatric patients. In addition, with chewable tablets, the act of chewing helps to break up the tablet particles as the tablet disintegrates and may increase the rate of absorption by the digestive tract.
Several workers in the field have explored rapidly disintegrative tablets. For example, U.S. Pat. No. 6,106,861 relates to a rapidly disintegrative tablet comprising an excipient and an active ingredient in the form of microcrystals coated with a coating agent. The excipient comprises at least one disintegration agent, which may be crospovidone or croscarmellose, and a soluble diluent agent that is a polyol either in directly compressible form or in powder form. The polyol is selected from the group consisting of mannitol, xylitol, sorbitol, and maltitol.
U.S. Pat. No. 5,464,632 describes another rapidly disintegrative tablet, the excipient mixture of which is suitable for imparting a very short disintegration time in the mouth. The excipient mixture comprises one or more disintegrating agents of the carboxymethylcellulose type or insoluble reticulated PVP type, one or more swelling agents, and possibly a direct compression sugar such as dextrose.
U.S. Pat. No. 6,024,981 relates to a hard tablet that can be stored, packaged and processed in bulk, but dissolves rapidly in the mouth. The tablet comprises an active ingredient mixed into a matrix of a non-direct compression filler and a lubricant.
PCT Application No. WO 99/47126 discloses compressed tablets capable of rapidly dissolving in aqueous solutions, comprising at least one non-saccharide water soluble polymer such as polyvinylpyrrolidone, optionally a saccharide of low moldability such as glucose, optionally a saccharide of high moldability such as maltose, sorbitol or a mixture thereof, and optionally a sweetener such as sucralose. These tablets are prepared by wet granulation, specifically a) granulating a formulation comprising the non-saccharide, water soluble polymer and active ingredient using no organic solvents, (b) compressing this into tablet form, (c) humidifying the tablet by exposing it to an aerated environment having at least about 50 to 100% relative humidity, and (d) drying the tablet. The object of PCT Application No. WO 99/47126 is to form a hard tablet.
Applicants have now discovered that a soft, chewable or disintegrative tablet may be prepared from a mixture comprising a pharmaceutically active ingredient, an excipient in the form of a hydrate, and a water-swellable excipient. A tablet having a friability of less than about 2% is first produced, preferably by direct compression, and then subjected to sufficient energy for a sufficient amount of time to decrease the hardness of the tablet by at least about 20%. In a preferred embodiment, the tablet is packaged after the tableting step but before the application of energy. Prior to the application of energy, the tablet is sufficiently hard to withstand handling and packaging operations, and is softened only after it is in its package. The final product delivered to the consumer is a soft tablet capable of being chewed or disintegrated in the mouth before swallowing.
The present invention provides a process for preparing a chewable or disintegrative tablet, comprising forming a tablet having a friability of less than about 2% from a mixture comprising a pharmaceutically active ingredient, an excipient in the form of a hydrate, and a water-swellable excipient, and then applying sufficient energy to the tablet for a sufficient time to decrease the hardness of the tablet by at least about 20%.
The invention also provides a tablet capable of being chewed or disintegrated in the oral cavity prior to swallowing, comprising a) a pharmaceutically active ingredient, b) an excipient at least partially in the form of a hydrate, and c) a water-swellable excipient that is at least partially hydrated.